A senior U.S. diplomat says political infighting in Sri Lanka should not jeopardize the peace process there. The diplomat also says future aid to Sri Lanka will be tied to respect for human rights.

Christina Rocca, the U.S. Assistant Secretary of State for South Asian affairs, encouraged Sri Lanka's president and prime minister to end a bitter dispute that threatens the stability of the government. The fight has cast a shadow over efforts to end Sri Lanka's 19-year civil war.

President Chandrika Kumaratunga and Prime Minister Ranil Wickremesinghe share power in a so-called cohabitation government. They are political enemies and their latest dispute involves who controls the state lottery. President Kumaratunga, who has the power to dismiss the prime minister and call new elections, also opposes the Norwegian-backed peace talks with the Tamil rebels. Mr. Wicremesinghe supports the talks.

Wrapping up a four-day visit on Wednesday, Ms. Rocca said the political quarrel should not impede peace efforts.

The political infighting follows a Tamil Tiger decision to boycott a conference next month in Tokyo, where donor nations are expected to pledge significant aid for reconstructing the war-battered nation.

The rebels are boycotting the meeting to protest having been barred from a donor conference in Washington. The United States has outlawed the group as a terrorist organization.

The rebels have also suspended participation in the Norwegian-brokered peace talks, saying the government has not done enough to resettle thousands of Tamil refugees. However, the rebels say they will continue to honor a ceasefire that has been in effect since last year.

Paikiasothy Saravanamuttu, who heads a Colombo policy research group, says both sides will find a way to overcome their differences. "The issue here is as to whether this is an indication that the process [peace] is in some sort of terminal decline and that it is going to be abandoned or jettisone," said Paikiasothy Saravanamuttu. "I do not think it is irredeemable. There are very definite positive gains from the cease-fire period that we have been having, which both sides cannot turn their backs on."

The civil war between Sri Lanka's Tamil minority and Sinhalese majority has cost the lives of at least 65,000 people and disrupted the island's once-vibrant economy.

During her visit, U.S. diplomat Christina Rocca pledged that international efforts to bring peace would continue. In a sign that diplomatic efforts may be intensifying, Norway's Foreign Minister Jan Peterson has arrived in Sri Lanka to talk with government and Tamil leaders.